Trump aides meet with congressional supporters as massive protest looms in New York
Republican presidential candidate Donald Trump (C) tried to defuse an intra-party feud that may be the only serious obstacle on his path to wining the Republican White House nomination (AFP Photo/Gaston De Cardenas)

Donald Trump campaign aides were meeting in Washington with congressional supporters on Thursday in a bid to improve relations with the Republican Party, as groups opposing his lightning-rod presidential run planned demonstrations at Trump appearances in New York state.

About a half dozen Congress members who have endorsed Trump met first thing Thursday morning near the U.S. Capitol, where the campaign told them they believed the Republican front-runner can secure enough delegates to win the nomination ahead of the party's July 18-21 convention. and other progressive groups, meanwhile, were calling for thousands of demonstrators who oppose Trump's positions on immigration and other issues to descend on a state party gala in New York City and a fundraiser in the Long Island town of Patchogue, a suburb that is home to a large Latino population.

The Capitol Hill meeting came as the anti-establishment Trump was trying to broaden his appeal in order to secure party support and win the Republican nomination to run in the November election.

Trump announced on Wednesday that he had hired Rick Wiley as his national political director. Wiley, a longtime Republican strategist, was the campaign manager for Scott Walker, the Wisconsin governor who dropped out of the presidential race last autumn.

One source said a series of policy speeches that Trump was preparing to deliver might come up in the Washington meeting. Trump himself was not attending, but senior adviser Ed Brookover did.

U.S. Representative Chris Collins of New York said the campaign told those at the meeting that they saw a path to securing 1,265 delegates - 1,237 delegates are needed to win the nomination.

Emerging from the meeting, Brookover told Reuters it was a "back-of-the-envelope" calculation.

Trump, a New York billionaire who has battled the Republican establishment, is seeking converts to his cause. Many Congress members had backed other Republican presidential candidates who have since abandoned the race.

Trump himself is engaged in a war of words with the Republican National Committee and its chairman, Reince Priebus, over party rules that, for example, allowed party regulars in Colorado to choose a slate of delegates to send to the party's nominating convention without Republicans in the state actually voting.

All the Colorado delegates went to U.S. Senator Ted Cruz of Texas, who is trying to stop Trump from gaining the 1,237-delegate majority needed to win the nomination on the first ballot at the convention in Cleveland in July.

Failure to win the first ballot would open the way to a contested convention at which Cruz, Ohio Governor John Kasich or an 11th-hour dark horse could theoretically win a second or subsequent ballot and become the party's nominee.

Going into New York's primary election on Tuesday, Trump holds a wide lead in opinion polls. He has been campaigning intensely in his home state.

On Thursday evening, Trump was to address a fund-raising event in Patchogue, the site of the fatal stabbing of Ecuadorean immigrant Marcelo Lucero in 2008 by a teenager who was part of a gang of white youths who targeted Latinos in the area.

The fundraiser's venue is near where Lucero was attacked, and immigrant advocates have planned protests there. Suffolk County Police Commissioner Timothy Sini said several different demonstrations coinciding with the event were expected.

After the fundraiser, Trump and Republican rivals Cruz and Ohio Governor John Kasich were to appear at the New York Republican Gala in Manhattan.

Progressive organizations have called for thousands of protesters on social media sites such as Facebook. The gala is near Grand Central Terminal in Midtown, a busy railroad station, and demonstrations could snarl rush-hour traffic in the nation's most populous city.

(Additional reporting by Doina Chiacu, Amanda Becker; Editing by Leslie Adler and Jonathan Oatis)